There are many replacement SMS apps available for Android and I’ve tried most of them. Some work alright, some are bloated and others are just rubbish. The best SMS app is that bundled with CyanogenMod - mainly because of the wonderful quick-reply functionality you get and the speed of the app.
Thankfully someone has finally decided to take all that lovely CyanogenMod functionality and bundle it as an app and put it on the Play Store. I’ve been testing it on my HTC One running Android 4.4 with Sense 5 and it works beautifully.